When I tried to run your code on my OpenRB-150 powered and controlled via the standard setup as shown on the ROBOTIS e-manual:
I had no problem compiling your code but downloading it via USB Port was a problem.
But I think that I have figured out your problem and that your OpenRB-150 must have been from an early batch used for Beta Testers which had some issues between its USB Port and when using DXLs that require 12 V (like XL430). I discovered this problem some months back, and I posted here
In that post, Will Son proposed one solution, but I prefer to power my DXLs separately at 12V and control them via the OpenRB-150 set at 5 V. See my setup below:
You can see that the OpenRB-150 Jumper is set on 5V (using Power from USB Port ), and I do not use the Power Terminal Block on the OpenRB-150. I used a separate Power Supply (via a U2D2 Power Hub) to power my DXLs at 12 V. From the U2D2 Power Hub to the XL-430s and between the DXLs, regular X3P cables are used. Please make sure to note that the last X3P cable (that connects to the X3P Hub on the OpenRB-150) has its VDD Line cutoff (hidden inside that white tape area). Essentially, the OpenRB-150 controls the DXLs at 5V and this Control Circuit is separate from the 12V Power Circuit of the DXLs, but both circuits have the same Ground.
Then your code worked fine for my setup, but I did reduce VELOCITY_LIMIT to 265:
If all this is a hassle to you and you recently bought your OpenRB-150 from ROBOTIS, you should try to ask for a replacement so that you get one from the regular commercial batch which does not have this problem. See setup below with a commercial OpenRB-150 and I have verified that your code worked fine on this commercial setup (with no cut-up X3P cable and the Jumper is on the VIN-DXL setting).
This “commercial” one has a QC tag number 2234. Which QC number do you have on yours OpenRB-150?